Fenton-like oxidation of landfill leachate

The treatment of stabilized leachates by means of Fenton's like reagent [Fe(III)-H2O2] has been studied. It has been demonstrated that the oxidation state of the catalyst does not influence the efficacy of the process in terms of chemical oxygen demand depletion profiles. The abrupt increase in temperature experienced in oxidation experiments involves a wastage of hydrogen peroxide diminishing the fraction of this reagent addressed at removing COD. If temperature is kept constant, the hydrogen peroxide uptake is 10 mg of H2O2 consumed per mg of COD abated (from 15 to 30°C). Working temperatures above 30°C does not lead to additional COD conversion, contrarily, the percentage of wasted H2O2 is increased. A rough economic analysis of the process indicates that this treatment can be a suitable alternative to deal with this type of effluents

Study of different integrated physical-chemical + adsorption processes for landfill leachate remediation

Some integrated processes to deal with landfill leachates have been investigated and their efficiencies expressed in terms of chemical oxygen demand (COD) removal. The systems tested were the result of different combinations of the following single stages: acidic pH shift (elimination of humic substances), ozonation (O3), coagulation-flocculation with Fe(III) salts, Fenton's oxidation (Fe(III) + H2O2), wet air oxidation (with or without radical promoters), and adsorption onto activated carbon (commercial Norit 0.8 powdered activated carbon). COD removals obtained ranged in the interval of 80-96% for initial COD values close to 11000 mg L-1. None of the processes tested reduced the COD levels sufficiently to allow direct discharge; however, the ratio biochemical oxygen demand (BOD/COD was significantly increased (up to 1000% in some cases, i.e., from 0.1 to values above 1.0). Total carbon reduction achieved ranged from 60 to 94%, while complete decolorization (measured as the absorbance at 410 nm) was obtained in practically all the combinations investigate

Simulated solar driven photolytic ozonation for the oxidation of aqueous recalcitrant-to-ozone tritosulfuron. Transformation products and toxicity

The authors are grateful to Junta de Extremadura (Project IB16022), co-financed by the European Funds for Regional Development, for economically supporting this work. Moreover, it is also acknowledged the ‘Servicio de Análisis Elemental y Molecular (SAEM)’ of ‘Servicios de Apoyo a la Investigación de la Universidad de Extremadura (SAIUex)’ for the helping with the intermediate products analyses.This work reports the combination of ozone and solar radiation as an advanced oxidation process to remove the herbicide tritosufuron (TSF) in water. Firstly, the recalcitrance of TSF has been assessed, obtaining an ozonation second order rate constant of 5–154 M−1 min−1 in the range of pH from 5 to 8; while the rate constant with HOradical dot was found to be (1.8–3.1)·109 M−1 s−1. Secondly, the simultaneous application of simulated solar radiation in between 300 and 800 nm and ozone resulted positive in the oxidation rate of TSF. Mineralization extent was also higher. Less effective oxidation was achieved after limiting the radiation to the range 360–800 nm or 390–800 nm; also completely inappropriate for mineralization. Thirdly, the detected transformation products (TPs) demonstrated the vulnerability of TSF molecule to be attacked by HOradical dot in the sulfonylurea bridge. The combination of ozone and radiation of 300–800 nm led to the most effective removal of the TPs. Finally, after the photolytic ozonation treatment toxicity was also evaluated in terms of phytotoxicity towards the germination and root elongation of Lactuca Sativa seeds, and toxicity by immobilization tests of Daphnia Magna.Junta de Extremadura (Project IB16022)European Funds for Regional Developmen

Stabilized leachates: sequential coagulation–flocculation + chemical oxidation process

The combined sedimentation-chemical oxidation treatment of medium-stabilized landfill leachates has been investigated. The sequence of stages implemented was: (a) coagulation–flocculation by pH decrease (pH 2) to acidic conditions (COD removal ≈ 25% related to COD0 ≈ 7500 ppm); (b) coagulation–flocculation by Fe(III) addition (0.01 M) at pH 3.5 (COD removal ≈ 40% related to COD of supernatant after step (a); (c) Fenton (Fe(III) = 0.01 M; H2O2 = 1.0 M) oxidation (COD removal ≈ 80% related to COD of supernatant after step (a); and (d) coagulation–flocculation of Fenton’s effluent at pH 3.5 (COD removal ≈ 90% related to COD of supernatant after step (a). The use of Kynch theory allows for the design of clarifiers based on the amount of solids fed. For a general example of 1000 m3 day−1 of a feeding stream, clarifier area values of 286, 111 and 231 m2 were calculated for compacting indices of 3.7, 2.67 and 2.83 corresponding to the first, second and third consecutive sedimentation processes, respectively, (steps (a), (b) and (d))

Stabilized leachates: Ozone-activated carbon treatment and kinetics

Ozone has been used as a pre-oxidation step for the treatment of stabilized leachates. Given the refractory nature of this type of effluents, the conversion of some wastewater quality parameters has been moderate after 1 h of ozonation (i.e. 30% chemical oxygen demand (COD) depletion). Ozone uptake was calculated in the interval 1.3–1:5 g of ozone per gram of COD degraded. An optimum dose of ozone has been experienced in terms of biodegradability of the processed effluent (60 min of treatment, 1 103 mol L1 ozone inlet feeding concentration and 50 L h1 gas flowrate). pH and other typical hydroxyl radical generator systems exerted no influence on the efficiency of the process, suggesting the negligible role played by the indirect route of oxidation (generation of hydroxyl radicals). The ozonated effluent was thereafter treated in a second adsorption stage by using a commercial activated carbon. Removal levels up to 90% of COD in approximately 120 h were experienced for adsorbent dosages of 30 g L1 : Both steps, the single ozonation and the adsorption stage have been modelled by using different pseudoempirical models. r 2003 Elsevier Ltd. All rights reserved

Psychometric characteristics of the Spanish version of instruments to measure neck pain disability

[EN] Background. The NDI, COM and NPQ are evaluation instruments for disability due to NP. There was no Spanish version of NDI or COM for which psychometric characteristics were known. The objectives of this study were to translate and culturally adapt the Spanish version of the Neck Disability Index Questionnaire (NDI), and the Core Outcome Measure (COM), to validate its use in Spanish speaking patients with non-specific neck pain (NP), and to compare their psychometric characteristics with those of the Spanish version of the Northwick Pain Questionnaire (NPQ). Methods. Translation/re-translation of the English versions of the NDI and the COM was done blindly and independently by a multidisciplinary team. The study was done in 9 primary care Centers and 12 specialty services from 9 regions in Spain, with 221 acute, subacute and chronic patients who visited their physician for NP: 54 in the pilot phase and 167 in the validation phase. Neck pain (VAS), referred pain (VAS), disability (NDI, COM and NPQ), catastrophizing (CSQ) and quality of life (SF-12) were measured on their first visit and 14 days later. Patients' self-assessment was used as the external criterion for pain and disability. In the pilot phase, patients' understanding of each item in the NDI and COM was assessed, and on day 1 test-retest reliability was estimated by giving a second NDI and COM in which the name of the questionnaires and the order of the items had been changed. Results. Comprehensibility of NDI and COM were good. Minutes needed to fill out the questionnaires [median, (P25, P75)]: NDI. 4 (2.2, 10.0), COM: 2.1 (1.0, 4.9). Reliability: [ICC, (95%CI)]: NDI: 0.88 (0.80, 0.93). COM: 0.85 (0.75,0.91). Sensitivity to change: Effect size for patients having worsened, not changed and improved between days 1 and 15, according to the external criterion for disability: NDI: -0.24, 0.15, 0.66; NPQ: -0.14, 0.06, 0.67; COM: 0.05, 0.19, 0.92. Validity: Results of NDI, NPQ and COM were consistent with the external criterion for disability, whereas only those from NDI were consistent with the one for pain. Correlations with VAS, CSQ and SF-12 were similar for NDI and NPQ (absolute values between 0.36 and 0.50 on day 1, between 0.38 and 0.70 on day 15), and slightly lower for COM (between 0.36 and 0.48 on day 1, and between 0.33 and 0.61 on day 15). Correlation between NDI and NPQ: r = 0.84 on day 1, r = 0.91 on day 15. Correlation between COM and NPQ: r = 0.63 on day 1, r = 0.71 on day 15. Conclusion. Although most psychometric characteristics of NDI, NPQ and COM are similar, those from the latter one are worse and its use may lead to patients' evolution seeming more positive than it actually is. NDI seems to be the best instrument for measuring NP-related disability, since its results are the most consistent with patient's assessment of their own clinical status and evolution. It takes two more minutes to answer the NDI than to answer the COM, but it can be reliably filled out by the patient without assistanceS

Table Olive Manufacturing Wastewater Treatment Using the Peroxymonosulfate/Fe(III) System

Wastewater generated in table olive manufacturing processes (WWTOMP) is a seasonal waste difficult to manage due to the high salinity content. The treatment of WWTOMP has been accomplished by including a precoagulation stage with aluminum sulfate, oxidation using the peroxymonosulfate/Fe(III) system, and a final aerobic biological stage. The optimum conditions of precoagulation led to a chemical oxygen demand removal rate of roughly 30–35% without the need for pH adjustment. The peroxymonosulfate(PMS)/Fe(III) system was thereafter applied to the effluent after coagulation. The addition of PMS lowered the initial pH to acidic conditions (pH = 1.5–2.0). Under these operating conditions, the initial PMS concentration and the initial Fe(III) dose showed optimum values. An excess of the oxidant and/or the catalyst partially inhibited the process efficiency, and pH exerted a significant influence. COD removal was substantially increased as the pH of the solution was moved toward circumneutral values in the interval 5–4. Moreover, at pH values of 5 and 7, PMS was capable of reducing COD without the need for Fe(III) presence. The direct oxidation of organics by PMS or the generation of chloride-based oxidants (Cl2 or HClO) is suggested to occur in parallel to the radical attack from PMS decomposition. An attempt to biologically reduce the final COD to discharge limits failed, mainly due to the high salinity content; however, the 1:2 dilution led to the reduction in COD from 6 to 2 g L−1. Acclimated sludges or saline content reduction should be first considered

Influence of oxygen and free radicals promoters on the UV-254 nm photolysis of diclofenac

Diclofenac has been irradiated under UV-C light at 254 nm. The effect of some operating variables has been investigated. The kinetics of the process has been analysed by means of the corresponding quantum yield. The presence of free radical promoters has also been considered. Diclofenac initial concentration plays an important role in its conversion profile. First order kinetics is ruled out under the applied experimental conditions. The process efficiency is significantly enhanced if oxygen is bubbled instead of air. Diclofenac quantum yield values in the range ≈0.1–0.3 mol Einstein−1 were obtained depending on the operating conditions used (air or oxygen) and the kinetic methodology followed. The mineralization level achieved also increased from 30 to 80% when oxygen was sparged instead of air. The presence of free radicals promoters did not improve the diclofenac removal efficiency

El uso de videojuegos activos entre los adolescentes

En este artículo se analiza el uso de videojuegos activos por parte de una muestra de 570 adolescentes de 4º de ESO. Los datos, recopilados a través de un cuestionario de autoinforme, indican que el 86,7% de los adolescentes ha jugado alguna vez a videojuegos activos, el 53,2% posee en sus hogares las tecnologías necesarias para jugar a este tipo de videojuegos, pero sólo el 7,2% juega habitualmente. Las pruebas de Chicuadrado señalaron que es superior el porcentaje de chicos y adolescentes autóctonos que ha jugado alguna vez a videojuegos activos respecto al de chicas y adolescentes inmigrantes. Estas tecnologías están menos presentes en los hogares del alumnado inmigrante, aunque no existieron diferencias según sexo y nacionalidad en los altos porcentajes de adolescentes que no juegan habitualmente a videojuegos activos. Estudios como el presente son de interés para conocer el grado de adherencia de los adolescentes a un ocio digital de última generación que representa una alternativa de práctica física en una sociedad sedentaria y tecnológica

Psychosocial effects of surgery and physical activity in bariatric patients: a systematic review

Obesity has become one of the major health problems in current industrialized societies. The negative impact of morbid obesity (defined as having a Body Mass Index>40 kg/m2) in the health-related quality of life of patients is significant. Bariatric surgery is currently considered an effective treatment to achieve sustained weight loss in patients with severe obesity, after failure of non-invasive treatments. The role of physical activity for optimizing bariatric surgery outcomes is receiving growing attention. In this sense, the aim of this article was to review the scientific literature concerning the psychosocial effects of surgery and physical activity in bariatric patients. The search was performed using Medline and Scopus databases. From a total of 58 articles, 37 articles were included in the review after the application of exclusion and inclusion criteria. In view of the evidence collected in this review, this article finishes with several conclusions and recommendations linking current knowledge with future research and future health-care interventions with this population.La obesidad se ha convertido en uno de los principales problemas de salud en las sociedades industrializadas actuales. El impacto negativo de la obesidad mórbida (definida como tener un índice de masa corporal > 40 kg/m2) en la calidad de vida de los pacientes es  preocupante. La cirugía bariátrica se considera actualmente un tratamiento eficaz para lograr la pérdida de peso sostenida en pacientes con obesidad severa, tras el fracaso de los tratamientos no invasivos. El papel de la actividad física para la optimización de los resultados de la cirugía bariátrica está recibiendo cada vez más atención. En este sentido, el objetivo de este artículo fue revisar la literatura científica sobre los efectos psicosociales de la cirugía y la actividad física en los pacientes bariátricos. La búsqueda se realizó utilizando las bases de datos Medline y Scopus. De un total de 58 artículos, 37 fueron incluidos en la revisión después de la aplicación de los criterios de exclusión e inclusión. A la vista de las evidencias recogidas en esta revisión, este artículo finaliza con algunas conclusiones y recomendaciones que vinculan el conocimiento científico actual con las futuras investigaciones e intervenciones de atención sanitaria con esta población